Snow pushers are well known apparatus for clearing snow and other materials or debris from surfaces such as roadways, driveways, parking lots, runways and other areas, as described for example in U.S. Pat. Nos. 5,724,755 and 6,112,438 to Weagley, hereby incorporated by reference in their entirety. Snow pushers are typically engaged with a bucket or quick coupling mechanism on a vehicle such as a front end loader, backhoe, skid steer loader, etc., and are pushed along to remove snow. Side plates are attached on the opposite ends of a moldboard for increasing the volume of snow that can be moved by the snow pusher. More specifically, the side plates serve the function of containing the snow in front of the moldboard and between the side plates, such that the snow continues to be gathered by the snow pusher.
One aspect of the disclosed embodiments provides for a pivoting wear shoe that remains in total contact with the surface, independent of the pusher angle or downward force applied to the scraping edge. Accordingly, it is an object of the disclosed embodiments to provide a wear shoe having an axis of rotation adjacent or near the front or distal end of the wear shoe and associated side plate in combination with a limiting slot at the opposite or proximal end. In order to control the range of the pivot, the wear shoe and/or side plate may include a slot and pin, bolt or bushing passing through the slot to provide limited motion based upon the length of the slot.
A skid plate or wear shoe on a conventional material pushing machine is securely affixed to the bottom edge of the side plate and is, by design, subjected to extensive abrasion resulting from the contact between the wear shoe and the roadbed or other surface over which the pusher travels. This wearing action is exacerbated when the snow pusher wear shoes are not positioned parallel to the surface, whereby only a portion of the available wear shoe surface is in direct contact with the roadbed. As a result the friction is increased over a small area causing uneven wear, and the lower surface plate of the wear shoe prematurely wears through and must be replaced more often. This is an expensive proposition because of down time of the machine and the cost expended in manpower and materials to replace the wear shoe.
A snow pusher further includes a scraper blade that is removably attached along the entire length of the bottom portion of the moldboard. The attributes of the scraper are threefold: (i) the material is selected based upon anticipated needs (e.g., soft edge such as rubber or polymer for light snow; hard steel edge on polymer backing for hard-packed snow and ice)moldboard, and becomes a sacrificial member that wears during use, as is the wear shoe, that protects the moldboard from wear; (ii) including a compliant material allows for the scraping edge to yield when a protrusion from the surface is encountered; and (iii) given various angles and downward pressure the scraping is better able to accommodate various snow conditions, ranging from ice to slush.
Typically, the wear shoes of a pusher control the distance separating the moldboard from the surface and thereby the amount of contact force between a scraping edge mounted on the bottom of the moldboard and the surface being plowed. However, given that the wear shoe and scraping edge are not readily adjustable on most pushers, as the scraping edge wears the ability to remove the snow or other materials down to the surface becomes more difficult. Currently either the scraping edge needs to be periodically adjusted downward to account for wear or be removed and then reattached in an alternate mounting orientation to re-establish the preferred amount of contact between the edge and the surface being cleaned. As will be further described below, the disclosed embodiments reduce or eliminate the need for periodic adjustment. Hence, one aspect of the disclosed embodiments is the ability of the front-pivoting wear shoe to permit a broad range of use and force to be applied to the scraping edge without the need to continually adjust the attachment position of the scraping edge relative to the bottom of the moldboard. For example, in one embodiment, a 4-5 inch range of motion is contemplated, which provides for an extended period of use without adjustment or replacement of the scraping edge.
As can now be appreciated, a significant and reoccurring problem with pushers having fixed wear shoes is that the operator often tilts the bucket upward in order to place the scraping edge of the pusher into greater contact with the surface being plowed (e.g., to increase down-pressure as the scraping edge wears and/or to scrape compacted snow from the surface). In doing so the wear shoe is no longer held parallel to the surface and uneven wear is encountered on the rear of the wear shoe. Moreover, the fixed mounting of the wear shoes prevents the application of varying downward pressure on the scraping blade. Therefore, it is believed to be desirable to provide a wear shoe that is pivotally attached to the side plate of the pusher, to allow the downward pressure applied to the moldboard and scraping edge to be varied without having to tilt the pusher or lift the front of the wear show off the surface.
One object of the disclosed embodiments to ensure that the wear shoe is compliant when a downward force is applied to the moldboard and scraping edge for completely clearing down to the surface.
Another object of the disclosed embodiments is to maximize the useful life of the wear shoes by promoting uniform contact with the surface.
Other objects, features and advantages will be evident from a reading of the following description and by reference to the accompanying drawings.
Disclosed in embodiments herein is a material pushing apparatus, comprising: an upstanding blade including an upper longitudinal edge, a lower longitudinal edge, a first vertical edge and a second vertical edge; a first vertical side plate extending forward from the first vertical edge of the blade; a second vertical side plate extending forward from the second vertical edge of the blade; a scraping edge attached along the lower longitudinal edge of the blade; and at least one wear shoe pivotally affixed to each of the first and second vertical side plates adjacent a front edge thereof, said wear shoe having a locus for the axis of rotation at a point distal from the cutting edge.
Further disclosed in embodiments herein is a snow pusher for plowing a surface, comprising: an upstanding blade having a first longitudinal edge and a second longitudinal edge including a first vertical edge and a second vertical edge; a first vertical side plate extending forwardly, at a right angle from the first vertical edge, of the blade; a second vertical side plate extending forwardly from the second vertical edge, of the blade; a scraper member attached to the first longitudinal edge of the blade, said scraper member being of a material that will be abraded by the surface; at least one wear shoe rotationally affixed to each of the first and second vertical side plates having a locus for the axis of rotation at a distal point from the cutting edge; and a vehicle, operatively attached to the snow pusher, said vehicle applying force to both drive the pusher forward and to maintain the scraping edge in contact with the surface.
The various embodiments described herein are not intended to limit the disclosure to those described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the various embodiments and equivalents set forth. For a general understanding, reference is made to the drawings. In the drawings, like references have been used throughout to designate identical or similar elements. It is also noted that the drawings may not have been drawn to scale and that certain regions may have been purposely drawn disproportionately so that the features and aspects could be properly depicted.